﻿// Parts Copyright 2008 Newgrove Consultants Limited
// Modified By John Diss 
// From original work:
//
// Copyright 2006 - Ricardo Stuven (rstuven@gmail.com)
//
// This file is part of MsSqlSpatial.
// MsSqlSpatial is free software; you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
// 
// MsSqlSpatial is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Lesser General Public License for more details.

// You should have received a copy of the GNU Lesser General Public License
// along with MsSqlSpatial; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 

using System.Data.SqlTypes;
using GeoAPI.DataStructures;
using GeoAPI.Geometries;
using Microsoft.SqlServer.Server;
using MsSqlSpatial;

public partial class UserDefinedFunctions
{
    [SqlFunction(IsDeterministic = true)]
    public static SqlBytes InteriorRingN(SqlBytes ewkb, SqlInt32 index)
    {
        IGeometry geometry = ConvertGeometry.ToGeometry(ewkb);
        if (geometry != null)
        {
            try
            {
                if (geometry is IPolygon)
                {
                    return
                        ConvertGeometry.ToSqlBytes(
                            Enumerable.First(Enumerable.Skip((geometry as IPolygon).InteriorRings, index.Value - 2)));
                }
            }
            catch
            {
            }
        }
        return SqlBytes.Null;
    }
} ;